Add free inode metric for Prometheus (#12225)

cmd/erasure.go

@@ -197,6 +197,7 @@ func getDisksInfo(disks []StorageAPI, endpoints []string) (disksInfo []madmin.Di
 				RootDisk:       info.RootDisk,
 				Healing:        info.Healing,
 				State:          diskErrToDriveState(err),
+				FreeInodes:     info.FreeInodes,
 			}
 			di.PoolIndex, di.SetIndex, di.DiskIndex = disks[index].GetDiskLoc()
 			if info.Healing {

cmd/metrics-v2.go

@@ -93,6 +93,7 @@ const (
 	timestampTotal MetricName = "timestamp_total"
 	writeTotal     MetricName = "write_total"
 	total          MetricName = "total"
+	freeInodes     MetricName = "free_inodes"
 
 	failedCount   MetricName = "failed_count"
 	failedBytes   MetricName = "failed_bytes"
@@ -352,6 +353,16 @@ func getClusterDisksTotalMD() MetricDescription {
 	}
 }
 
+func getClusterDisksFreeInodes() MetricDescription {
+	return MetricDescription{
+		Namespace: clusterMetricNamespace,
+		Subsystem: diskSubsystem,
+		Name:      freeInodes,
+		Help:      "Total free inodes.",
+		Type:      gaugeMetric,
+	}
+}
+
 func getNodeDiskTotalBytesMD() MetricDescription {
 	return MetricDescription{
 		Namespace: nodeMetricNamespace,
@@ -1386,6 +1397,12 @@ func getLocalStorageMetrics() MetricsGroup {
 					Value:          float64(disk.TotalSpace),
 					VariableLabels: map[string]string{"disk": disk.DrivePath},
 				})
+
+				metrics = append(metrics, Metric{
+					Description:    getClusterDisksFreeInodes(),
+					Value:          float64(disk.FreeInodes),
+					VariableLabels: map[string]string{"disk": disk.DrivePath},
+				})
 			}
 			return
 		},

cmd/storage-datatypes.go

@@ -32,6 +32,7 @@ type DiskInfo struct {
 	Free       uint64
 	Used       uint64
 	UsedInodes uint64
+	FreeInodes uint64
 	FSType     string
 	RootDisk   bool
 	Healing    bool

cmd/storage-datatypes_gen.go

@@ -14,8 +14,8 @@ func (z *DiskInfo) DecodeMsg(dc *msgp.Reader) (err error) {
 		err = msgp.WrapError(err)
 		return
 	}
-	if zb0001 != 12 {
+	if zb0001 != 13 {
-		err = msgp.ArrayError{Wanted: 12, Got: zb0001}
+		err = msgp.ArrayError{Wanted: 13, Got: zb0001}
 		return
 	}
 	z.Total, err = dc.ReadUint64()
@@ -38,6 +38,11 @@ func (z *DiskInfo) DecodeMsg(dc *msgp.Reader) (err error) {
 		err = msgp.WrapError(err, "UsedInodes")
 		return
 	}
+	z.FreeInodes, err = dc.ReadUint64()
+	if err != nil {
+		err = msgp.WrapError(err, "FreeInodes")
+		return
+	}
 	z.FSType, err = dc.ReadString()
 	if err != nil {
 		err = msgp.WrapError(err, "FSType")
@@ -83,8 +88,8 @@ func (z *DiskInfo) DecodeMsg(dc *msgp.Reader) (err error) {
 
 // EncodeMsg implements msgp.Encodable
 func (z *DiskInfo) EncodeMsg(en *msgp.Writer) (err error) {
-	// array header, size 12
+	// array header, size 13
-	err = en.Append(0x9c)
+	err = en.Append(0x9d)
 	if err != nil {
 		return
 	}
@@ -108,6 +113,11 @@ func (z *DiskInfo) EncodeMsg(en *msgp.Writer) (err error) {
 		err = msgp.WrapError(err, "UsedInodes")
 		return
 	}
+	err = en.WriteUint64(z.FreeInodes)
+	if err != nil {
+		err = msgp.WrapError(err, "FreeInodes")
+		return
+	}
 	err = en.WriteString(z.FSType)
 	if err != nil {
 		err = msgp.WrapError(err, "FSType")
@@ -154,12 +164,13 @@ func (z *DiskInfo) EncodeMsg(en *msgp.Writer) (err error) {
 // MarshalMsg implements msgp.Marshaler
 func (z *DiskInfo) MarshalMsg(b []byte) (o []byte, err error) {
 	o = msgp.Require(b, z.Msgsize())
-	// array header, size 12
+	// array header, size 13
-	o = append(o, 0x9c)
+	o = append(o, 0x9d)
 	o = msgp.AppendUint64(o, z.Total)
 	o = msgp.AppendUint64(o, z.Free)
 	o = msgp.AppendUint64(o, z.Used)
 	o = msgp.AppendUint64(o, z.UsedInodes)
+	o = msgp.AppendUint64(o, z.FreeInodes)
 	o = msgp.AppendString(o, z.FSType)
 	o = msgp.AppendBool(o, z.RootDisk)
 	o = msgp.AppendBool(o, z.Healing)
@@ -183,8 +194,8 @@ func (z *DiskInfo) UnmarshalMsg(bts []byte) (o []byte, err error) {
 		err = msgp.WrapError(err)
 		return
 	}
-	if zb0001 != 12 {
+	if zb0001 != 13 {
-		err = msgp.ArrayError{Wanted: 12, Got: zb0001}
+		err = msgp.ArrayError{Wanted: 13, Got: zb0001}
 		return
 	}
 	z.Total, bts, err = msgp.ReadUint64Bytes(bts)
@@ -207,6 +218,11 @@ func (z *DiskInfo) UnmarshalMsg(bts []byte) (o []byte, err error) {
 		err = msgp.WrapError(err, "UsedInodes")
 		return
 	}
+	z.FreeInodes, bts, err = msgp.ReadUint64Bytes(bts)
+	if err != nil {
+		err = msgp.WrapError(err, "FreeInodes")
+		return
+	}
 	z.FSType, bts, err = msgp.ReadStringBytes(bts)
 	if err != nil {
 		err = msgp.WrapError(err, "FSType")
@@ -253,7 +269,7 @@ func (z *DiskInfo) UnmarshalMsg(bts []byte) (o []byte, err error) {
 
 // Msgsize returns an upper bound estimate of the number of bytes occupied by the serialized message
 func (z *DiskInfo) Msgsize() (s int) {
-	s = 1 + msgp.Uint64Size + msgp.Uint64Size + msgp.Uint64Size + msgp.Uint64Size + msgp.StringPrefixSize + len(z.FSType) + msgp.BoolSize + msgp.BoolSize + msgp.StringPrefixSize + len(z.Endpoint) + msgp.StringPrefixSize + len(z.MountPath) + msgp.StringPrefixSize + len(z.ID) + z.Metrics.Msgsize() + msgp.StringPrefixSize + len(z.Error)
+	s = 1 + msgp.Uint64Size + msgp.Uint64Size + msgp.Uint64Size + msgp.Uint64Size + msgp.Uint64Size + msgp.StringPrefixSize + len(z.FSType) + msgp.BoolSize + msgp.BoolSize + msgp.StringPrefixSize + len(z.Endpoint) + msgp.StringPrefixSize + len(z.MountPath) + msgp.StringPrefixSize + len(z.ID) + z.Metrics.Msgsize() + msgp.StringPrefixSize + len(z.Error)
 	return
 }
 

cmd/storage-rest-common.go

@@ -18,7 +18,7 @@
 package cmd
 
 const (
-	storageRESTVersion       = "v32" // Added transition related information to FileInfo
+	storageRESTVersion       = "v33" // Added transition related information to FileInfo
 	storageRESTVersionPrefix = SlashSeparator + storageRESTVersion
 	storageRESTPrefix        = minioReservedBucketPath + "/storage"
 )

cmd/xl-storage.go

@@ -471,6 +471,7 @@ func (s *xlStorage) DiskInfo(context.Context) (info DiskInfo, err error) {
 			dcinfo.Free = di.Free
 			dcinfo.Used = di.Used
 			dcinfo.UsedInodes = di.Files - di.Ffree
+			dcinfo.FreeInodes = di.Ffree
 			dcinfo.FSType = di.FSType
 
 			diskID, err := s.GetDiskID()